Bit guide



4, 1966 c. E. WAKEFIELD, JR 3,

BI'Il GUIDE Filed Aug. 28, 1963 NVENTOR.

BY 2/ WM United States Patent M 3,227,229 r I BIT GUIDE Charles E. Wakefield, Jr., Bakersfield, Calif.,:assignor-to Richi'ield Oil Corporation, .Los Angeles, Calif a corporation of Delaware Filed Aug. 28, 1963, Ser. No. 305,237 Claims. (Cl. 175-7) tioned on the well in a formation underlying a body of water.

In my copending application SJN. 100,411 filed April 3, 1961 for Submarine Drilling and Production Head and Method of Installing Same, a submarine well head is described which can be installed on the floor underlying a body of water without extensive diving operations which would be required in the submarine installation of conventional Christmas tree type well heads in order to bolt down the various well head components. The [above application also describes a method for landing the casing in two sections whereby the upper section .of casing is lowered integrally with the outer mandrel .of the production or well head assembly. In thisspecific instance,

as well as other situations, drilling can be advantageously accomplished by lowering the drill bit into the well through the well head which well head has finished surfaces therein against which various sealing means are applied to seal off against the pressure of well @fiuids. Since the drill bit is lowered on a drill pipe from a drilling structure such as a platform or a drilling barge some considerable distance above the well head, the drill bit maybe subject to lateral movement as it is lowered into the hole through the casing riser pipe into the well head apparatus having finished or sealing surfaces. Consequently, these surfaces are susceptible to damage by bit contact and may be marred or skinned by thedrill bit as it is lowered through such well head apparatus into the well, which marring prevents them from serving as effective sealing or seating surfaces.

Accordingly, it is a principal object of the present invention to provide means and a method for lowering a drill bit subject to lateral movement, through apparatus having finished surfaces without marring such surfaces.

It is also an object of thepresent invention to provide a bit guide for directing a drill bit through well head apparatus having finished surfaces without marring the finished well head surfaces.

It is a further object of my present invention to provide a means for supporting a bit guide in a submarine well head.

Other objects and a fuller understanding of my invention may be had by referring to the following description and the appended claims taken in conjunction with the accompanying drawings in which:

FIG. 1 shows in partial cross section an elevation of a well apparatus utilizing the preferred form of my present invention;

FIG. 2 shows in partial cross section a modification of my present invention.

Briefly described, my invention relates to a bit guide adapted to span the sealing surfaces of a submarine Well head against which various sealing means seal and which hit guide can be remotely installed within the well head by latching the bit guide with a conventional blowout preventer.

Referring more particularly to FIG. 1, the apparatus of my present invention is shown in its preferred form,

Patented Jan. "4, 1966 positioned in-a submarine well head. A production head such as production mandrel 10 may be positioned at the ocean floor in a conductor casing '(not shown) and has blowout preventer 12 latched thereto. A bit guide 14 extends into the production mandrel-as shown and is sup ported near its upper end withlatching gates'18 of blowout preventer 15. With bit guide 14 in positiomas shown in the drawing, the drill bit 16 may be lowered from -a conventional drilling structure 58 through the riser 56 and the production head on drill string 17 without injuring the internal finished surfaces of the production mandrel 10.

Referring more particularly to the drawingsfthe production mandrel 10 which is described more fully in my above-mentioned copending application, is afiixed to the formation by cementing its lower end portion 20 into the conductor pipe in a submarine well (not shown). The production mandrel 10 is supported in the well head prior 'toibeing cemented in by landing shoulder 21 of lower end portion 20 on top of a drilling mandrel (not shown) as taught in my aforementioned copending application. Blowout preventer 12 is utilized to .latch the casing riser 56 onto the well head or mandrel 10, although any convenient means may be employed .for connecting the riser 56 tothe well head. The latch gate 22 ofblowout preventer 12 may be of the conventional hydraulic single gate type or any convenient latch mechanism. A tubing hanger mandrel (notshown) is adapted to seat within the production mandrel so that well production flows through the tubing and out through a side outlet :in the tubing hanger mandrel and throughithe production mandrel side outlet 26 which registers with the side outlet of the tubing hanger mandrel. The tubing =l1angermandrel (not shown) has seals which seal around the inside of the tubing side outlet 26 against the inside surface 31 of the production mandrel. The production mandrel is provided internally with sealing surface 33 and the seating portion 32 on which the tubing hanger mandrel is supported Within the production mandrel. These sealing and seating surfaces within the production mandrel are the finished surfaces which can be serious- 1y damaged by contact with a drill bit 16 as it is lowered through the production mandrel into the well.

A bit guide 14 is lowered into the hole with, for example, a J-slot connector on a releasable tool (not shown) connected to the drill pipe until the lower end 30 of the bit guide extends below the seating area 32 and .the upper shoulder 34 of the bit guide rests on the shoulder area 36 of the production mandrel. The shoulder portion 34 serves primarily to position the bit guide within the well head. With the bit guide lowered into the well head on the drill pipe so that the bit guide engages shoulder 36, a laterally movable latch gate 18 in the blowout preventer 15 is actuated to latch the bit guide at its latching neck 40, thus preventing rotation or upward movement of the bit guide by movement of the drill string therethrough. The latch gate 18 may be any of the conventional laterally movable latching equipment preferably of the hydraulic single gate type.

The bit guide can also be held or latched as shown in FIG. 2 with pins 48 actuated hydraulically or manually (as shown) through the spool 41, in which case the blowout preventer 15 is used as a latching device may be eliminated.

The blowout preventer 12 has a flange member 42 fastened to the lower end thereof, which flange member seats on the lugs 44 provided on the production mandrel 10, to limit the downward movement of the blowout preventer 12 over the production mandrel 10. A scuttling spool. 46 is connected atop blowout preventer 15 and conventional blowout prevention equipment and the casing riser 56 are provided above spool 46 to perform the usual function of preventing blowouts and conveying drilling fluids from the well to the drilling structure 58.

With the bit guide 14 latched at 40 by the latch gate 18, the drill bit 16 may be lowered through the bit guide on a drill string 17 and through the sealing and seating surfaces of the production head or other well head equipment and into the well where it may be operated for deepening the hole, removing cement plugs, etc. A drilling structure 58 located at or above the water surface may house any appropriate means for operating the drill bit 16, as for example, the drilling apparatus shown in copending application of William D. Leake, Serial No. 19,722 filed April 4, 1960, entitled Drilling Apparatus and Method.

Although I have described my present invention with a certain degree of particularity in order to set forth the best mode of operation, it is to be understood that my invention is not to be limited to the details set forth but should be given the full scope of the appended claims.

I claim:

1. In a well head apparatus through which a drill bit subject to lateral movement with respect to said well head may be passed including a well head production mandrel having sealing surfaces therein and laterally movable means in said well head apparatus for latching said well head apparatus to said production mandrel, the improvement comprising:

an elongated tubular member adapted to be lowered into said production mandrel adjacent said sealing surfaces,

and laterally movable means for latching said tubular member to said well head apparatus.

2. In a well head apparatus through which a drill bit subject to lateral movement with respect to said well head may be passed including a well head production mandrel having a reduced section therein and sealing surfaces internally therein and laterally movable means in said well head apparatus for latching said well head apparatus to said production mandrel, the improvement comprising:

an elongated tubular member having a reduced section therein adapted for lowering into said production mandrel adjacent said sealing surfaces, and laterally movable means for latching said tubular member to said well head apparatus.

3. In a well head apparatus through which a drill bit subject to lateral movement with respect to said well head may be passed, including a well head mandrel having sealing surfaces therein and laterally movable means in said well head apparatus for latching said well head apparatus to said mandrel, the improvement comprising:

an elongated tubular member adapted to be lowered into said mandrel adjacent said sealing surfaces, and

laterally movable means for latching said tubular member to said well head apparatus.

4. In an underwater drilling apparatus wherein a well head apparatus having a passageway therethrough with sealing surfaces therein and through which passageway a drill bit subject to lateral movement with respect to said said well head apparatus may be passed, said well head apparatus being positioned under a drilling structure located near the Water surface with a riser extending between said drilling structure and said well head apparatus and including means for connecting said riser to said well head apparatus, the improvement comprising:

a tubular member adapted to be lowered into said well head apparatus and into said well head apparatus passageway adjacent said sealing surfaces to protect said surfaces from damage by said drill bit as said drill bit is lowered through said well head apparatus, and

means for latching said tubular member to said well head apparatus.

5. In an underwater drilling apparatus wherein a well head apparatus having a central bore therethrough with sealing surfaces therein and through which bore a drill bit subject to lateral movement with respect to said bore may be passed, said well head apparatus being positioned under a drilling structure located near the water surface with a riser extending between said drilling structure and said well head apparatus and including means for connecting said riser to said well head apparatus, the improvement comprising:

a bit guide adapted to be lowered into said well head apparatus and into said well head apparatus adjacent said sealing surfaces of said bore to protect said surfaces from damage by said drill bit as said drill bit is lowered through said well head apparatus, and laterally movable latch means for connecting said bit guide to said well head apparatus.

References Cited by the Examiner UNITED STATES PATENTS 1,769,921 7/1930 Hansen -10 2,010,992 8/1935 Howard 166-80 2,638,169 5/1953 Crain 166-85 2,808,229 10/1957 Bauer et al 175-7 2,927,642 3/ 1960 Meredith 166-46 X 2,995,196 8/1961 Gibson 175-7 3,032,125 5/1962 Hiser 175-7 3,137,348 6/1964 Ahlstone et a1. 166-665 X FOREIGN PATENTS 1,221,911 6/1960 France.

CHARLES E. OCONNELL, Primary Examiner. 

1. IN A WELL HEAD APPARATUS THROUGH WHICH A DRILL BIT SUBJECT TO LATERAL MOVEMENT WITH RESPECT TO SAID WELL HEAD MAY BE PASSED INCLUDING A WELL HEAD PRODUCTION MANDREL HAVING SEALING SURFACES THEREIN AND LATERALLY MOVABLE MEANS IN SAID WELL HEAD APPARATUS FOR LATCHING SAID WELL HEAD APPARATUS TO SAID PRODUCTION MANDREL, THE IMPROVEMENT COMPRISING: 